The Pope endorsed Paul VI’s 1968 encyclical re-affirming the Church’s stance on abortion, contraception and other issues of human life, and said “the basic lines of Humanae Vitae are still correct”.

Speaking to Peter Seewald during a six-hour interview, the Pope discussed the Church’s teaching on sexuality, including Paul VI’s encyclical, which was controversial because many expected the Church would change its teaching on contraception at the time.

Paul VI, he said, “was convinced that society robs itself of its greatest hopes when it kills human beings through abortion”.

Benedict XVI said: “How many children are killed who might one day have been geniuses, who could have given humanity something new, who could have given us a new Mozart or some new technical discovery?

“We need to stop and think about the great human capacity that is being destroyed here – even quite apart from the fact that unborn children are human persons whose dignity and right to life we have to respect.”

Humanae Vitae’s main argument, that sexuality separated from fecundity in principle through the contraceptive pill would lead to sexuality becoming arbitrary, remains correct, Pope Benedict said.

He said: “Logically, every form of sexuality is of equal value. This approach to fecundity as something apart from sexuality, so far apart that we may even try to produce children rationally and no longer see them as a natural gift, was, after all, quickly followed by the ascription of equal value to homosexuality.”

The Pope also briefly touched on the problem of presenting the Church’s teaching on sexuality to a society that was ignoring it.

Despite high numbers of people not following the Church’s teaching on sexual ethics, the Pope said that “statistics do not suffice as a criterion for morality”.

“Finding ways to enable people to live the teaching on the other hand is a further question,” the Pope said. “I think that there will always be core groups of people who are really open to being interiorly convinced and fulfilled by the teaching and who then carry everyone else. We are sinners. But we should not take the failure to live up to this high moral standard as an authoritative objection to the truth.

“We should try to do as much good as we can and to support and put up with each other. We should also try to express the teaching pastorally, theologically, and intellectually in the context of today’s studies of sexuality and anthropology so as to create the conditions for understanding so that people can realize that this is a great task on which work is being done and on which even more and better work needs to be done.”

Pope Benedict also repeated that the Church supported the “natural regulation of conception” because it was “not just a method but a way of life” and presupposes that couples take time for each other.

Therefore, he said, natural methods of regulation are “something fundamentally different from when I take the pill without binding myself interiorly to another person, so that I can jump into bed with a random acquaintance”.